Is "Basic Service" the same thing as "Flight Information Service" in ICAO language?
I think that's the intention.
But you won't get this kind of service in the UK. You can call up e.g. London Info for weather for some airport, for an airways join (if e.g. departing from a grass strip on an airways flight) and such. But I am hard pushed to think of a reason why one would want to be voluntarily in contact with a Basic Service otherwise.